There are two distinct regions in which coral reefs are primarily distributed: the Wider Caribbean (Atlantic Ocean) and the Indo-Pacific (from East Africa and the Red Sea to the Central Pacific Ocean).

- The diversity of coral is far greater in the Indo-Pacific, particularly around Indonesia, the Philippines, and Papua New Guinea. Many other groups of marine fauna show similar patterns, with a much greater diversity in the Indo-Pacific region.

- Although they possess a smaller number of species the corals of the Atlantic are still unique, with few common species between the two regions (Spalding et al., 2001).

Major threats to the world’s coral reefs include overexploitation and coastal development. This graphic explains the activities or conditions that threaten the world’s various reefs, and shows the global distribution of destroyed coral reefs. In addition, the global warming that the world is beginning to experience is likely to have a major impact on coastal and marine environments:

- The sea has an enormous capacity to store heat. Warmer water, combined with anticipated changes in ocean currents, could have a devastating impact on marine ecosystems and biodiversity.

- One potential result could be a reduction in the upwelling of nutrients, which would in turn reduce productivity in key fishing areas.

- Decreased growth may also be seen in coral reefs, with high concentrations of CO2 in the water impairing the deposition of limestone required for coral skeletons (UNEP, 2002).